Domain Matching Epitaxy of Ferroelectric Hf0.5Zr0.5O2(111) on La2/3Sr1/3MnO3(001)

TL;DR

This study demonstrates the epitaxial growth of ferroelectric Hf0.5Zr0.5O2(111) films on La2/3Sr1/3MnO3(001) substrates through an unconventional domain matching epitaxy mechanism, despite significant lattice mismatch and symmetry differences.

Contribution

It reveals that domain matching epitaxy enables the stabilization of ferroelectric Hf0.5Zr0.5O2(111) films on dissimilar substrates, expanding understanding of epitaxial mechanisms in complex oxide heterostructures.

Findings

Epitaxial Hf0.5Zr0.5O2(111) films were stabilized on La2/3Sr1/3MnO3(001).

Dislocation arrays observed match domain matching epitaxy predictions.

Unconventional epitaxy mechanism explains stabilization despite lattice mismatch.

Abstract

Epitaxial ferroelectric HfO2 films are the most suitable to investigate intrinsic properties of the material and for prototyping emerging devices. Ferroelectric Hf0.5Zr0.5O2(111) films have been epitaxially stabilized on La2/3Sr1/3MnO3(001) electrodes. This epitaxy, considering the symmetry dissimilarity and the huge lattice mismatch, is not compatible with conventional mechanisms of epitaxy. To gain insight into the epitaxy mechanism, scanning transmission electron microscopy characterization of the interface was performed, revealing arrays of dislocations with short periodicities. These observed periodicities agree with the expected for domain matching epitaxy, indicating that this unconventional mechanism could be the prevailing factor in the stabilization of ferroelectric Hf0.5Zr0.5O2 with (111) orientation in the epitaxial Hf0.5Zr0.5O2(111)/La2/3Sr1/3MnO3(001) heterostructure.